Valveless vane compressor

ABSTRACT

A vane compressor has a plurality of vanes that are radially translatable and have outer ends. The vanes create zones between each pair of adjacent vanes, each zone having a given area. The vane compressor also has an axis about which the vanes rotate and an outlet for expelling compressed fluid. A first zone immediately following a second zone, which is in register with the outlet, has the same area as the second zone.

BACKGROUND

This application relates to vane compressors, and more particularly to avalveless vane compressor.

Vane compressors compress fluids, such as gas, and are well known in theart. A vane compressor may have internal disk in which a plurality ofvanes are free to move in and out of the disk. The vanes follow an outercircumference and take in fluid when the vanes are extended from thedisk, and compress the fluid as the vanes follow the circumference andcontract thereby lessening the area in which the fluid is entrapped. Thecompressed fluid is pushed out of a fluid outlet. To prevent the fluidfrom back flowing into a vane compressor, valves are typically disposedwithin the fluid outlet to prevent such back flow. As the compressordrive shaft rotates, the vanes slide in and out to make contact with thecompressor wall. Fluid enters at the largest opening and the compressedfluid discharges from the smallest opening. Vane compressors may utilizea centered drive shaft and a shaped outer surface or an offset driveshaft and a circular outer surface.

SUMMARY

According to an example disclosed herein, a vane compressor has aplurality of vanes that are radially translatable and have outer ends.The vanes create zones between each pair of adjacent vanes, each zonehaving a given area. The vane compressor also has an axis about whichthe vanes rotate and an outlet for expelling compressed fluid. A firstzone immediately following a second zone that is in register with theoutlet has the same area as the second zone.

According to a further example disclosed herein, a method of compressingfluid is provided. The method includes the steps of inletting a fluidhaving a first area; compressing the fluid by decreasing the first areato a smaller second area; rotating the second area to a first zoneimmediately leading a second zone having an outlet; rotating the secondarea to the second zone; and outletting the fluid from the second zoneto reduce backflow from the outlet.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of the disclosed examples willbecome apparent to those skilled in the art from the following detaileddescription. The drawings that accompany the detailed description can bebriefly described as follows.

The FIGURE shows a schematic view, partially in phantom, of a vanecompressor as described herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the FIGURE, a vane compressor 10 is shown. The vanecompressor 10 is of the balance type, however, one of ordinary skillwould recognize that this teachings may be usable in other types of vanecompressors, balanced or non-balanced, and with central off centerdrives or centered drives, etc. The vane compressor 10 has a disk 15that rotates about axis 20, a cam surface 25, slots 30, vanes 35, inlets40 and outlets 45. The dimensions shown in the FIGURE are exaggeratedfor ease of observation. As shown herein, the vane compressor 10 rotatesin a clockwise direction.

Within the disk 15, the vanes 35 translate during rotation of the disk15 within the slots 30 so that there is contact between the cam surface25 and the vanes 35. The vane compressor 10 is a balanced vanecompressor and has two inlets 40 and two outlets 45 distributed aroundand through the cam surface 25. Though fourteen vanes 35 are shownherein, one of ordinary skill will recognize that other numbers of vanes35 are utilizable herein.

As the disk 15 and the vanes 35 rotate, areas of variable size arecreated between the vanes 35. As shown in the FIGURE, there are 14 zonesdesignated from A to N as will be discussed herein.

Zones A, B and C, which all have the same or similar area, form anoutlet zone O. Zone B is in register with an outlet 45 of outlet zone O.Similarly, zones H, I and J, which all have the same or similar area,form a similar outlet zone P where zone I is in register with outlet 45of outlet zone P. In outlet zone O and outlet zone P, the vanes 35 inregister therewith are in a stowed position within the relevant slots 30as they follow first contour 50 in the cam surface 25. The first contour50 of the cam surface 25 in outlet zone P has a constant length radius55 emanating from axis 20. The area of zones A, B, and C, and the areaof zones H, I, J, is minimized and carry compressed fluid, such as air,therein.

Zones D and K form compression zones as the variable vanes 35 move froman extended position relative to the slots 30 to a stowed position whilefollowing a diminishing second contour 60 thereby limiting (e.g.,diminishing) the area of zones D and K to the same area shown in zonesA, B and C forming outlet zone O and zones H, I and J forming outletzone P respectively. The diminishing second contour 60 has a radius 65emanating from axis 20 that diminishes from a length of a radius 70 inzone E to the same length of radius 55 as in outlet zones O and P.

Zones F and E and Zones M and L all have the same or similar area and aconstant radius 70 following third contour 75 of the cam surface 25.

Zones F and G, and N and M are each in register with a fluid inlet 40.Zones N and G represent expansion areas where the vanes 35 move from astowed position to an extended position to allow fluid to move thereinand the fourth contour 80 which attaches the first contour 50 to thethird contour 75. Zones E and L each have the same area as the precedingzones M and F to prevent back flow of fluid from zones E and L to thezones M and F respectively because the pressure in those zones are thesame. Zones N and G have an extending arc 85.

As previously mentioned, zones K and D compress in area, therebycompressing the fluid therein, so that the zone C and the correspondingzone J have fluid at the proper pressure to export the pressurized fluidthrough the outlets even though zones C and J do not align with anoutlet 45. If the zones C and J are not fully compressed until theyreach zones I and B, then as the vane between B and C or I and J passesthe outlet 45 there may be back flow into zones C or J. As zone C movesto zone B and zone J moves to zone I though it is clear that thepressure of the fluid is proper to outlet through the outlets 45 withoutsignificant backflow into the zones I or B. By waiting another zone toexpel the fluid compressed in zones C or J, the two aft vanes in zones Oand P, in essence form a seal to reduce back flow.

Waiting a zone to export the fluid through an outlet 45 after the fluidis compressed, allows a vane compressor 10 to be built without valvesfor preventing back flow. Similarly, zones A and H are also maintainedat the same area as zones B and I, respectively. If zones A and H wereallowed to expand in area by allowing the vanes 35 to move outwardlyalong the cam surface 25 in zones A and H, the drop in pressure in thosezones may pull fluid from an outlet 45 through zones I and Brespectively causing undesirable back flow from an outlet 45. By waitinga zone, the two forward vanes and the two aft vanes in zones O and P, inessence form a seal to reduce back flow. As a result, by extending thevanes in zones N and M a full zone past an outlet 45, a backflowprevention valve at an outlet 45 is unnecessary.

Functionally, by keeping the area of zones A, B and C substantiallyconstant as they create outlet zone O can prevent the need for back flowvalves (not shown). The area in those zones is kept substantiallyconstant herein by maintaining the substantially constant arc in thefirst contour 50 of the cam surface 25 in those zones. This is also truein outlet zone P which includes zones H, I and J.

Similarly, vanes surrounding zones L and E are kept at a substantiallyconstant distance from the axis 20 to the cam surface 25 as theimmediately preceding zones M and F which are in register with theinlets 40. This prevents back flow of fluid as it is compressed in zonesK and D to reduce back flowing through the inlet 40 and wasting energyof compressing the fluid.

Although a combination of features is shown in the illustrated examples,not all of them need to be combined to realize the benefits of variousembodiments of this disclosure. In other words, a system designedaccording to an embodiment of this disclosure will not necessarilyinclude all of the features shown in the FIGURE or all of the portionsschematically shown in the FIGURE. Moreover, selected features of oneexample embodiment may be combined with selected features of otherexample embodiments.

The preceding description is exemplary rather than limiting in nature.Variations and modifications to the disclosed examples may becomeapparent to those skilled in the art that do not necessarily depart fromthe essence of this disclosure. The scope of legal protection given tothis disclosure can only be determined by studying the following claims.

1. A vane compressor, said vane compressor comprising: a plurality ofvanes that are radially translatable and have outer ends wherein saidplurality of vanes create zones between each pair of adjacent vanes,each of said zone having a given area; an axis about which said vanesrotate; a first outlet for expelling compressed fluid; and, wherein saida first zone immediately following a second zone in register with saidfirst outlet has the same area as the second zone.
 2. The vanecompressor of claim 1 further comprising a third zone immediatelyleading said second zone in register with said first outlet, said thirdzone having the same area as the second zone.
 3. The vane compressor ofclaim 2 further comprising a fourth zone immediately leading said thirdzone said fourth zone having an area greater than said third zone. 4.The vane compressor of claim 1 further comprising a first inlet.
 5. Thevane compressor of claim 4 further comprising a fifth zone downstream ofsaid first zone in register with at least a portion of said first inlet,said fifth zone having a greater area than said second zone.
 6. The vanecompressor of claim 4 further comprising a sixth zone adjacent saidfifth zone and in register with at least a portion of said first inlet,said sixth zone having an area that is greater than said area of saidsecond zone and is greater than the area of said fifth zone.
 7. The vanecompressor of claim 6 further comprising a seventh zone adjacent saidsixth zone, said seventh zone having an area that is the same area assaid sixth zone.
 8. The vane compressor of claim 7 further comprising aneighth zone adjacent said seventh zone and a third zone immediatelyleading said second zone in register with said first outlet, said thirdzone having the same area as the second zone, said eighth zone having anarea less than an area of said seventh zone and greater than said areaof said third zone.
 9. The vane compressor of claim 4 further comprisinga second outlet and a second inlet.
 10. The vane compressor of claim 9further comprising a second set of first zones and second zones.
 11. Thevane compressor of claim 10 further comprising a second set of fifthzones downstream of said first zone in register with at least a portionof said first inlet, said second set of fifth zone having a greater areathan said second zone; a second set of sixth zone said second set ofsixth zones in register with at least a portion of said second inlet,said second set of sixth zone having an area that is greater than saidarea of said second zone and is less than the area of said second set offifth zone; a second set of seventh zone adjacent said second set ofsixth zone, said second set of seventh zone having an area that is thesame area as said second set of sixth zone; and a second set of eighthzone adjacent said second set of seventh zone and a third zoneimmediately leading said second zone in register with said secondoutlet, said third zone having the same area as the second zone, saidsecond set of eighth zone and having an area less than an area of saidsecond set of seventh zone and greater than said area of said thirdzone.
 12. The vane compressor of claim 1 further comprising a camsurface that engages or is in close proximity to said outer ends. 13.The vane compressor of claim 12 wherein said cam surface has a firstcontour defined by a constant radius emanating from said axis, saidfirst contour defining an outer edge of said first and second zones. 14.The vane compressor of claim 13 wherein said first contour defines anouter edge of a third zone immediately following said second zone. 15.The vane compressor of claim 13 further comprising a second contour saidsecond contour immediately leading said first contour, said secondcontour having a diminishing radius to compress fluid within zones inregister with said second contour.
 16. The vane compressor of claim 15wherein said second contour includes a single zone.
 17. The vanecompressor of claim 13 further comprising a third contour, said thirdcontour immediately following said first contour, said second contourhaving an increasing radius to receive fluid from an inlet in zones inregister with said third contour.
 18. A method of compressing fluid,said method comprising: inletting fluid having a first area; compressingsaid fluid by decreasing said first area to a smaller second area;rotating said second area to a first zone immediately leading a secondzone having an outlet; rotating said second area to said second zone;and outletting said fluid from said second zone to reduce backflow fromsaid outlet.
 19. The method of claim 18 further comprising: rotatingsaid second area to a third zone immediately following said second zone.20. The method of claim 18 further comprising: expanding said secondarea to said first area in zones following said third zone.